Die for bending angle bars



Dec. 24, 1940. A. HOSSFELD 2,225,742

DIE FOR BENDING ANGLE BARS Filed Feb. 14, 1938 2 Sheets-Sheet 1 Dec. 24, 1940. A. HOSSFELD ,2

DIE FOR BENDINGANGLE BARS Filed Feb. 14, less 2 Sheets-Sheet 2 7% /rvg Patented Dec. 24, 1940 UNITED STATES PATENT OFFICE DIE FOR BENDING ANGLE BARS Albert Hossfeld, Winona, Minn.

Application February 14, 1938, Serial No. 190,442

10 Claims.

My present invention relates to bending machines, and moreparticularly, to such a machine of the type disclosed in my prior United States Letters Patent No. 1,832,201, issued of date No- 5 vember 17, 1931, and entitled Die for bending angle bars.

The machine disclosed in the above identified patent is designed for use in bending angle bars, while cold, about an axis perpendicular to one 10 flange of the bar and at one side thereof and with the outer edge of said flange on the concave side of the bend.

In bending an angle bar, as heretofore stated, the upsetting of certain parts of the metal and 15 the stretching of other partsthereof produces a stress in thebar which causes the same to twist or distort away from its original plane and also to distort the bar fromits original angle shape to an acute angle shape. i

so It is an object of this invention to provide an angle bar bending die that will generate opposing pressures that will counteract the stresses, heretofore mentioned, and. bend the bar in a perfect 28 plane and without distorting its right angle shape. I a

It is a further object of the invention to provide for these various opposing pressures being generated automatically thus requiring for its operao ation only one direction of pressure power, such as may be supplied by a power bulldozer press, or,

as shown in this application, by a pair of handoperated pivoted frames.

These and other objects and. advantages of the invention will be fully set forth in the following description made in connection with the drawmgs.

To the above end, generally stated, the 'inven-' tion consists of the novel devices, combinations of devices and arrangement of parts hereinafter described and defined in the claims;

In the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. 1 is a fragmentary plan view of the device with some parts shown in section;

Fig. 2 is a fragmentary detail view principally in section taken on the line 22 of Fig. 1;

50 Fig. 3 is a detail view in section taken on the line33 of Fig. 1; i

Fig. 4 is a detail view partly in side elevation and partly in section taken on the line 4-4 of Fig. 1;

66 Fig. 5 is a fragmentary detail view with some parts sectioned on the irregular line 5-5 of Fig. 4;

Fig. 6 is a face View ofthe master die;

Fig. 7 is a plan view of the same;

Fig. 8 is a face view of the die radius block, tilted slightly for movement into the master die; and i Fig. 9 is a plan view of the same.

Of the parts of the hand-operated bending machine showing the embodiment of my present invention, it is only necessary to note the frame l0 and the bending arm ll. Said frame ID includes a pair of vertically spaced bars I2, the flat sides of which are parallel and rigidly connected by nut-equipped bolts and spacing members. This frame Ill further includes front and rear leg brackets l3 bolted to the bench or other support, not shown.

The bending arm H has fixed to its inner end portion a pair of vertically spaced bars M, the flat sides of which are parallel. These pairs of bars l2 and M are connected by a pivot pin IS with the bars l4 outwardly of the bars [2 and bearing thereon. This pivot pin 15 connects the bending arm .II to the frame in for swinging movement in a horizontal plane.

For the purpose of showing the device in an operative position, there is illustrated in the drawings an angle bar x, the horizontal flange of which is designated by the letter y and the vertical flange of which is designated by the letter 2. It will be noted that the angle bar a: is fed in a horizontal position endwise to the device with its horizontal flange turned toward the axis about which the bar is bent, or in other words, on the concave side of the bend in the bar a.

Referring now to the subject-matter of this invention, the same includes a die comprising a relatively fixed die member l6 and a co-operating movable die member [1, hereinafter referred to as the radius block.

On the vertical face of the die member I6, at the bottom thereof, is a relatively narrow surface I8 formed on the arc of a circle having a predetermined radius. Formed in the die member I6, above its surface I8, is an angle groove ill, the bottom surface 20 of which slopes inwardly and .upwardly toward the vertical axis, about which the bend in the bar'zn is made. The transverse width of the bottom surface 20 is constant and somewhat wider than the flange y which rests thereon with the outer face of the flange z substantially at the die surface 18. It will be noted that the entire area of the bottom surface 2|) is flat and in the same plane, see Fig. 6. The wall surface 2| of the angle groove I9 is perpendicular to the bottom surface 20 and extends to the top of the die member [6, and its upper edge is on the arc of a circle having a radius less than the radius of the surface I8, so thatthe bottom surface 20 extends considerably outwardly from under the top of the die member |6.

Integral with the wall surface 2| is a pair of parallel laterally spaced and outwardly projecting lugs 22 having wedge-acting surfaces 23 on their under sides. The tops of the lug 22 are flush with the top of the die member l6 and their outer ends are substantially directly above the die surface l8. By reference to Fig. 3 it will be noted that the wedge-acting surfaces 23 incline in a reverse direction from the bottom surface 20, over which they lie, and that the inner ends of said surfaces 23 are spaced above the bottom surface 20 at the junction of the wall surface 2| therewith.

The radius block H has a convex outer surface 24 formed on the arc of a circle having a radius corresponding to the bend to be made in the bar .73. This radius block has a flat bottom surface 25 that is parallel to the bottom surface 20 and rests on the flange y with the outer surface 24, which is perpendicular to said surface 25, engaging the inner face of the flange a. It is on this surface 25 that the flange a is bent and determines the radius of the curve to be made in the bars. The back of the wedge block I! is concave and concentric with the surface 2| of the angle groove l9. On the end portions of the radius block H are wedge-acting surfaces 25, which engage the wedge-acting surfaces 23 and are reversely inclined in respect thereto. Obviously, the co-operatingwedge-acting surfaces 23 and 26 will move the radius block 40' I! downwardly, when inward pressure is applied to said block and thereby grip the flange y between the die members l6 and |'|,'see Fig. 3. The top of the radius block I1 is parallel to the bottom thereof, and at the inner ends of the 5 wedge-acting surfaces 26 are stop shoulders 21 which engage the lugs 22 at their inner faces and thereby hold the radius block I! against endwise movement relative to the die member l6, and hold said radius block centered in reference to the die member IS. The upper rear edge portion of the radius block I1 is beveled at 28.

In actual usage of the bending machine, the same will be provided with interchangeable radius blocks H, the surface 24 of each of which will be formed on a different radii for making bends in angle bars of different diameters.

The invention further includes a pairof novel devices 29 and 30 for holding the bar a: at each I 60 end of the die members l6 and I1. One of these devices, to wit: 29 is disposed between the bars I2 and includes a block 3| pivoted at 32 to said bars for swinging movement about a vertical axis. The face of the block 3| is vertically parallel to the bending surface 24 on the die member H for contact with the outer face of the flange z to hold the same against movement away from the radius member I1. In the face of the block 3| is a shallow vertical channel 33, and at the sides of which said block has twopoint contact with the flange e at longitudinally spaced points. The purpose of the channel 33 is to adapt the block 3| to bars being bent on different radii and afford suflicient clearance to insure two-point contact therewith. Ob-

viously, the block 3| affords an abutment for the bar 1;, and to hold said bar against lifting movement from the bottom surface 20 of the die member IS, a bolt 34 is turnably mounted in a sleeve bearing 35 formed with the block 2| at the outer upper corner thereof. This bolt 34 is perpendicular to the bending surface 24, and the front end portion thereof projects outwardly of the sleeve bearing 35 and is undercut or notched to form a shoulder 36 having a flat under surface which is engageable with the upper edge of the flange z. Cooperating internal and external shoulders 31 on the sleeve bearing 35 and the bolt 34 hold said bolt against endwise movement into said bearing, and a cotter pin 38 in the projecting rear end of said bolt holds said bolt against outward endwise movement in the sleeve bearing 35.

The holding device 30 is identical with the holding device 29 except that it is for the righthand side of the die instead of the left-hand side thereof. Only the following parts of the device 30 are shown in Fig. 1, to wit: the block 39, channel 40, pivot 4|, bolt 42 and sleeve bearing 43.

The operation of the bending device may be briefly described as follows: First, the bending arm H is swung from its position shown in Fig. 1 toward the frame II] to be out of the way when placing the bar a: in the die, and said bar is held in a horizontal position with its flange y resting on the bottom surface 20 of the die member l6, and then moved endwise to position its flange 2 under the bolt 34. Next, the radius block I! is placed on the flange y with its bending surface 24 against the inner face of the flange 2 at substantially the point on the bar a: where the bending is to start. Said bar a; is then endwise moved to bring the radius block into proper alignment with the die member l6, and thereafter said bar is moved horizontally to position the radius block I! in the die member IS with its wedge-acting surfaces 26 in engagement with the wedge-acting surfaces 23. The bending lever is then swung in the direction of the arrow marked on Fig. 1 to bring the bending block 39 into contact with the outer face of the flange z and the bolt 42 over the upper edge of said flange. Further movement of the bending arm I! in the same direction will bend the flange 2 around the surface 24 of the radius block I! and shape the flange y to the same radius, as heretofore stated. This bending of the bar a: upsets certain parts thereof and places stress in the bar, tending to twist the same on its transverse axis and tilt the bar a: upwardly and toward the vertical axis about which the bar is bent.

Pressure required to bend the bar a: forces the radius block I! into the die member l6 and the co-operating wedge-acting surfaces 23 and 26 force said block I! onto the flange y and said flange onto the bottom surface 24 of the die member l6. During the bending of the bar :1:, the holding devices 29 and 3|], due to the plane of the face 20 being tilted downward at an obtuse angle with the pivot pin 5 and at an acute angle with the pivot pins 32 and 42, a downward stress is created on the free ends-of the bar suflicient to resist the natural tendency of same to turn upward and causing the bar to bend in a perfect plane. This downward stress is determined by the degree of angle given the face 20 in relation to the pins I5, 32 and 4|. Due to the novel co-operating surfaces of the die members It and II, the web 11 of the bar a: at the point where the bending action is taking place, is held in a vise-like grip, thus preventing the same from buckling or twisting. This pressure is also yielding to the natural upsetting and thickening of the web y as the bending action takes place. The amount of this pressure is determined by the degree of angle given the faces 23 and 26 to the face 26. Each stroke of the bending arm H bends the bar a: for a relatively short distance, at the completion of each of said strokes, the bending arm II is returned to its starting point and said bar is moved endwise in the direction of the arrow to feed a further section of said bar into the said die. These operations are repeated until the desired degree of bend has been completed.

By pivotally attaching the devices 29 and 30 to the bars 12 and 14, respectively, they will automatically adjust themselves for two-point contact with the flange z in the various different positions of the bar :0. Likewise, the turnably mounted bolts 34 and 42 will move the flange a so that their shoulders 36 always have flat contact with the upper edges of said flange.

The above described device is capable of vari ous modifications within the scope of the invention herein disclosed and claimed.

What I claim is:

1. In a bending machine, a die having opposing surfaces for gripping one of the flanges of an angle bar when it is horizontally disposed therebetween and holding the angle bar with its other flange upwardly disposed, said die also having a bending surface, means acting to hold that portion of the upwardly disposed flange which is subjected to bending against movement in the plane thereof and in a direction away from the flange held by the gripping surfaces, and means for bending the angle bar on the bending surface, said gripping surfaces and the bending surface holding the angle bar with its flanges transversely oblique to the plane of movement of the bending means.

2. In a bending machine, a die having a pair of co-operating surfaces for gripping one of the flanges of an angle bar when it is horizontally disposed therebetween and holding the angle bar with its other flange upwardly disposed, said die also having a curved bending surface substantially perpendicular to said surfaces and arranged to be engaged by the upwardly disposed flange at its inner face, means acting to hold that portion of the upwardly disposed flange which is subjected to bending against movement in the plane thereof and in a direction away from the flange held by the gripping surfaces, and means for bending the angle bar on the curved bending surface, said gripping surfaces and the bending surface holding the angle bar with its flanges transversely oblique to the plane of movement of the bending means. i

3. In a bending machine, a die having a pair of co-operating members, one of which is relatively movable, said members having opposing surfaces for gripping one of the flanges of an angle bar when it is horizontally disposed therebetween and holding the angle bar with its other flang upwardly disposed, one of said members having a curved bending surface substantially perpendicular to the gripping surfaces and arranged to be engaged by the upwardly disposed flange, means acting to hold that portion of the upwardly disposed flange which is subjected to bending against movement in the plane thereof and in a direction away from the flange held by the gripping surfaces, and means for bending the angle bar on the curved bending surface, said gripping surfaces and the curved bending surface holding the angle bar with its flanges transversely oblique to the plane of movement of the bending means.

4. In a bending machine, a die having a pair of co-operating members, one of which is relatively movable, said members having opposing l surfaces for gripping one of the flanges of an angle bar when it is horizontally disposed there between and holding the angle bar with its other flange upwardly disposed, one of said members having a curved bending surface substantially perpendicular to the gripping surfaces and arranged to be engaged by the upwardly disposed flange, a pair of holding blocks having surfaces substantially parallel to said bending surface transversely thereof for holding the upwardly disposed flange against movement away from the bending surface, holding means extending over the top of the upwardly disposed flange at longitudinally spaced points and arranged to be engaged thereby, and means for moving one of the blocks to bend the angle bar on the bending surface, said gripping surfaces being transversely oblique to the plane of movement of the bending means.

5. The structure set forth in claim 4 in which the holding blocks are pivotally mounted and have two-point contact with the upwardly disposed flange at longitudinally spaced points.

6. The structure set forth in claim 4 in which each holding means is carried by one of the hold- 35 ing blocks.

7. The structure set forth in claim 4 in which each holding means is a bolt turnably mounted in one of the holding blocks.

8. The structure defined in claim 4 in which 15 each holding means is a bolt turnably mounted in one of the holding blocks, extends perpendicular to the bending surface and has a flat surface that engages the top surface of the upwardly disposed flange.

9. In a bending machine, a die having a pair of co-operating members, one of which is relatively movable, said members having opposing flat gripping surfaces, wedge means causing movement of the movable member, whereby said surfaces will grip one of the flanges of an angle bar when it is horizontally disposed therebetween, and. holding the angle bar with its other flange upwardly disposed, said movable member having a curved bending surface substantially perpendicular to the gripping surfaces and arranged to be engaged by the upwardly disposed flange at its inner face, a pair of pivotally mounted blocks having surfaces substantially parallel to the curved bending surface transversely thereof and engageable with the upwardly disposed flange at its outer face, each of said blocks having a turnable mounted bolt substantially perpendicular to the curved bending surface and extending transversely over the top of the upwardly disposed flange to be en- 65 gaged thereby, and means for moving one of the holding blocks substantially concentric with the curved bending surface to bend an angle bar on said curved surface.

10. The structure set forth in claim 4 in which 70 each holding block is pivotally mounted to turn about an axis parallel to the axis of the die and in which each holding means extends perpendicular to the upwardly disposed flange.

- ALBERT HOSSFELD. 

